FreeNAS is a free NAS server, supporting: CIFS (samba), FTP, NFS, AFP, RSYNC, iSCSI protocols, S.M.A.R.T., local user authentication, Software RAID (0,1,5) with a Full WEB configuration interface. FreeNAS takes less than 32MB once installed on Compact Flash, hard drive or USB key.
When I get finished I should have a mirrored 250GB of space with 2GB of Flash memory for various server plugins. I hope to get it configured as a media server to play my musice over the XBOX 360, but we'll see.